2018/02/16 by Quentin Pognan, Cecilia Garraffo, Ofer Cohen +1
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Angular momentum #Coronal mass ejection #Doppler effect #Geomagnetism and Paleomagnetism Studies #Ionosphere and magnetosphere dynamics #Magnetic field #Magnetopause #Solar and Space Plasma Dynamics #Solar physics #Solar wind #Wind profile power law #Wind speed #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aaaebb
21 pages, 11 figures, accepted for publication in ApJ, 8th February 2018
arxiv created 2018/02/16 · openalex created_date 2018/02/23 · openalex publication_date 2018/03/20 · arxiv updated 2018/04/11 · openalex updated_date 2026/08/06
Abstract We use magnetograms of eight solar analogs of ages 30 Myr–3.6 Gyr obtained from Zeeman Doppler Imaging and taken from the literature, together with two solar magnetograms, to drive magnetohydrodynamical wind simulations and construct an evolutionary scenario of the solar wind environment and its angular momentum loss rate. With observed magnetograms of the radial field strength as the only variant in the wind model, we find that a power-law model fitted to the derived angular momentum loss rate against time, t , results in a spin-down relation Ω ∝ t −0.51 , for angular speed Ω, which is remarkably consistent with the well-established Skumanich law Ω ∝ t −0.5 . We use the model wind conditions to estimate the magnetospheric standoff distances for an Earth-like test planet situated at 1 au for each of the stellar cases, and to obtain trends of minimum and maximum wind ram pressure and average ram pressure in the solar system through time. The wind ram pressure declines with time as , amounting to a factor of 50 or so over the present lifetime of the solar system.